/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package xml.timgiayto.controller;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.xml.transform.Result;
import javax.xml.transform.Source;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.sax.SAXResult;
import javax.xml.transform.stream.StreamSource;
import org.apache.fop.apps.Fop;
import org.apache.fop.apps.FopFactory;
import org.apache.fop.apps.MimeConstants;

/**
 *
 * @author mrnghiep
 */
public class CombineFOWithXSL extends HttpServlet {

    private FopFactory fopFactory = FopFactory.newInstance();
    private TransformerFactory tFactory = TransformerFactory.newInstance();

    /**
     * Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        try {
            String contextPath = getServletContext().getRealPath("/");
            //Setup a buffer to obtain the content length
            ByteArrayOutputStream out = new ByteArrayOutputStream();

            //Setup FOP
            Fop fop = fopFactory.newFop(MimeConstants.MIME_PDF, out);
            File config = new File(contextPath + "fo/fop.xconf");
            fopFactory.setUserConfig(config);
            //Setup Transformer

            Source xsltSrc = new StreamSource(contextPath + "xslt/informationFO.xsl");
            Transformer transformer = tFactory.newTransformer(xsltSrc);

            //Make sure the XSL transformation's result is piped through to FOP
            Result res = new SAXResult(fop.getDefaultHandler());
            //Setup input
            Source src = new StreamSource(contextPath + "xml/information.xml");

            //Start the transformation and rendering process
            transformer.transform(src, res);

            //Prepare response
            response.setContentType("application/pdf");
            response.setContentLength(out.size());

            //Send content to Browser
            response.getOutputStream().write(out.toByteArray());
            response.getOutputStream().flush();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
    /** 
     * Handles the HTTP <code>GET</code> method.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /** 
     * Handles the HTTP <code>POST</code> method.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /** 
     * Returns a short description of the servlet.
     * @return a String containing servlet description
     */
    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>
}
